1. Field of the Invention
The invention relates to the field of medical imaging using light.
2. Description of the Prior Art
Due to its relatively low cost and ease of implementation, optical imaging is an attractive technology to study intrinsic signals associated with endogenous chromophores as well as targeted exogenous probes. With the explosive growth in available molecular reporter strategies for studying fundamental biophysical processes, there has been a paradigm shift in research efforts from ex vivo destructive evaluation to in vivo analysis, allowing for characterization of dynamic biological processes and for each animal to serve as its own control. Despite these tremendous advances in molecular imaging, absolute quantification of the magnitude and origin of cellular and molecular events remains a significant challenge.
In the neuroscience community, optical imaging of intrinsic signals has long been used to study the organization and functional architecture of different cortical regions in animals and humans. Local changes in intrinsic signals have been attributed to an increase or decrease in local neurovascular activity, but separation of these signal dynamics into basis components such as oxy/deoxygenation of blood, changes in blood volume, and optical scattering, has not been performed, resulting in an incomplete picture of the underlying mechanisms. Technologic advances such as combined reflectance/fluorescence imaging, multi-parameter full-field imaging, and laminar optical tomography enable improved separation of the signals to study important parameters such as local tissue metabolic dynamics; however, these technologies currently can provide only relative changes in hemodynamic parameters and do so without consideration of optical scattering effects on extracted tissue parameters.
In U.S. Pat. No. 6,958,815 we presented a disclosure involving wide field, broadband, spatially modulated illumination of turbid media. This approach has potential for simultaneous surface and subsurface mapping of media structure, function and composition. This method can be applied with no contact to the medium over a large area, and could be used in a variety of applications that require wide-field image characterization. The approach described in U.S. Pat. No. 6,958,815 and a fluorescence imaging capability described in U.S. patent application Ser. Nos. 11/927,396 and 11/336,065, each incorporated herein by reference is further refined in the present disclosure.